The R-AXIS RAPID II Located at the Natural History Museum of Los Angeles County the Natural History Museum of L.A

MATERIALS ANALYSIS eNEWSLETTER OCTOBER 2013, ISSUE 4

The R-AXIS RAPID II located at the Natural History Museum of Los Angeles County The Natural History Museum of L.A. County, 900 Exposition Blvd., Los Angeles, CA 90007, Dr. Anthony R. Kampf, Curator Emeritus

The Natural History Museum of Los Angeles County opened on November 6, 1913 at Exposition Park in L.A. and has since grown to be the largest such museum in Dr. Kampf joined NHM in January 1977, after earning the western U.S. As Curator of Mineral Sciences for his Ph.D. in mineralogy and crystallography from the University of Chicago. The current mineral sciences lab at NHM developed around his knowledge of mineralogy, crystal chemistry and structural crystallography. He has analyzed countless unknown minerals and described 26 new minerals between 1975 and 2008. Interestingly enough, over 100 new minerals are still found by mineralogists every year around the world.

Dr. Anthony R. Kampf more than 34 years, Dr. Anthony R. Kampf was instrumental in building the museum’s extensive collection of gems and minerals, its beautiful gem and mineral exhibition, as well as performing scientific research in descriptive mineralogy and structural crystallography. Since retiring in 2011, Dr. Kampf Dr. Anthony R. Kampf and his R-AXIS RAPID II has continued his research as Curator Emeritus.

The R-AXIS RAPID II, one of Rigaku’s curved imaging to investigate by conventional XRD and so usually have plate X-ray diffraction systems, was installed at NHM by to be studied using EBSD (electron backscatter Dr. Kampf in November 2007. He needed to replace diffraction). The krotite in this inclusion was large enough obsolete powder and single-crystal XRD systems that that I was able to use the RAPID II. I first mounted the were film-based. He chose the R-AXIS RAPID II because entire microscope slide on the RAPID and recorded the it can measure both powder and single-crystal data. powder diffraction pattern of the krotite using reflection When Dr. Kampf is faced with an unknown mineral mode. I then succeeded in extracting a 110 x 60 x 20 µm phase, he first obtains an X-ray powder diffraction pattern crystal fragment, from which I collected single-crystal and performs a search against a database of known structure data. I obtained an excellent structure minerals. If the X-ray powder pattern does not match a refinement with R1 = 1.6%. For me the charm of scientific known mineral and occurs in crystals of sufficient size mineralogy comes from making discoveries, each of and quality, Dr. Kampf then pursues a single-crystal which helps us to understand the world around us a little study and structure analysis. The dual-purpose better. I was particularly happy to be a part of the team functionality of the R-AXIS RAPID II (powder and single that worked on krotite because it adds to our crystal) has proven ideal to Dr. Kampf’s work, allowing understanding of how our solar system formed. The him to quickly and easily switch between the two special feeling that comes from making a discovery is methods. In the 6 years since obtaining the R-AXIS what has kept me involved in research even after RAPID II, Dr. Kampf has characterized more than 75 new retirement. In fact, the only reason that I retired was so minerals, three times the number that he had that I could spend more time doing research and using characterized in the previous 33 years! the R-AXIS RAPID II, which has proven to be an essential and irreplaceable research tool.”

From left to right, Collections Manager Alyssa Morgan, Associate Curator Eloïse Gaillou,and Dr. Anthony R. Kampf

One of his signature XRD studies with the R-AXIS RAPID II was his work on the new mineral krotite in 2011 (American Mineralogist, Volume 96, pages 709–715, 2011). This phase is considered one of the earliest formed in our solar system. Dr. Kampf told us that the new mineral krotite, CaAl2O4, was found as the main component of a tiny inclusion in a meteorite. “Inclusions like this one are usually studied in thin- sections mounted on glass microscope slides. The phases in inclusions like this are almost always too small